Color photography



BLUE SENSITIVE LAYER CONTAINING GREEN SENSITIVE LAYER CONTAINING D, NICKEL GARBONATE LEAD cAR BONATE./ aYELLow DYE. RED SENSITIVE LAYER STRIPPING LAYER. CONTAINING FERRIC PAPER SUPPORT. HYDROXIDE8 PINK D E.

GREEN SEPARATION POSITIVE SILVER IMAGE 8 UNIFORMLY DISTRIBUTED NICKEL CARBONATE.

EXPOSE a DEVELOP LUE SEPARATION POSITIVE SILVER IMAGE fiUNlI'ORMII DISTRIBUTED LEAD CARBONATE,

R-ED SEPARATION POSITIVE LEAD FERROCYANIDE IMAGE FERRIC FERROCYANIDEIMAGE.

BLUE FERRIC FERROCYANIDE IMAGE MAGENTA NICKEL DIMETHYLGLYOXIME IMAGE STRIPPING LAYEVK/ I PAPER suPPoR TREAT WITH THE N WITH HCL TREAT WITH DIMETHYLGLYOXIME THEN WITH KgC OI; AND TRANSFER BY STRIPPING SILVER IMAGE-s UIIIFDRMLY K Fe(CN) DISTRIBUTED FERRIC IIYIIROXIIIE- NICKEL FERIZOCYANIDE IMAGE STRIPPING LAYER.

PAPE SUPPORT PERMANENT PAPER BLUE SENSITIVE LAYER WITHOUT ADDED suPPoRT/ cu RoMATE IMAGE REEN SENSITIVE METAL sALT./'

LAYER CONTAIN ING NICKEL CARBONATE RED SENSITIVE LAYER CONTAINING i FERRIG HYDROXIDEEIPINK DYE-l 3 8YELLOW DYE. I-ILM' SUPPORT. FILM SUPPORT.

. L GREEN SENSITIVE I I BLUE SENSITIVE TTTLAYER.

LAY R CONTAINING L NICKEL CARBONATE L & YELLow DYE.

FILM SUPPORT.

qfREo SENSITIVE Ln LAYER conmmme A FERRIC HYDROXIDE I 8 PINK DYE.

BLUE 'sEIIsmvE "LAYER. FILM SUPPORT RED SENSITIVE LAYER coummme FERRIC HYDROXIDE TILM SUPPORT.

E's PINK DYE BLUE SENSITIVE LAYER.

GREEN-SENSITIVE FILM suproat j l4 v GREEN SENSITIVE 1 LAYER CONTAINING 2 NICKEL CARBONATE i 8 YELLOW DYE.

RED SENSITIVE /LAYER CONTAINING LAYER WITHOUT FERRIG I'IYDROXIOE 8 PINK DYE.

ADDED METAL SALT.

FILM 5UPPORT./

ca gg rw i Patented Kpr. 23, .1940

PATENT orricr.

} 2.191.994 'ooLon. rno'roonsrnr Colin Butement, London, England, aslignor to Duiay-Ohromex Limited, London, England, a

British company Application August? 26. 1988, Serial No. 226,931

In Great Britain September 10. 1937 This invention consists in improvements in or relating to color photography and has for its object the provision of a new or improved light sensitive material which may be used either for taking or for copying and which may be processed to produce an image in color and more particularly, in magenta. A further object of the invention is to provide a method of processing the new or improved material. Still further objects are the provision, in one form of the invention, of new or improved light sensitive ma terial which may be processed, after exposure, to produce an additional colored image or images which combine with the magenta image to give a multi-color photograph and the provision of a method of processing this form of the material.

It is already known to incorporate in a silver halide emulsion layer organic color formers which react during development of the silver image by a suitable developer with the products of development to produce dyed gelatine images. It

has also been proposed to provide light sensitive material for use in the production of multl-color photographs consisting of three super-imposed layers of emulsion sensitised respectively to light covering the three wave-length regions customary in the three-color process and each containing a color former of the kind described above and so selected that on development and bleaching of the silver images colored images are pro- I duced in the three subtractive primary colors.

Further, it is known that colored images may beproduced by treating the silver salts pro-.

duced by bleaching a silver image with solutions of certain metal salts which reactwith the silver salts to produce colored metal compounds. The

metals and the salts of them which may be used ing a nickel compound (such as-nickel carbonate or nickel hydroxide) which is substantially inert to the silver halide but which may, by chemical treatment after exposure,

bleaching of the silver halide, be converted to one of the salts of nickel which is known to react with the silver salts produced by bleaching the silver image to provide a reaction product which is colored or may, by further treatment, be converted into a coloredproduct. v The invention also provides light sensitive phoproduct which is colored or may, by further development and tographic material for use in the production of colored images comprising a plurality of light sensitive layers carried on a support and sensitised to difierent-regions of the spectrum, each layer containing a compound of one of the known metals hereinbefore referred to which is substantially. inert to the silver halide but which may, by chemical treatment after exposure, de-

the layers being selected to provide products of 1s diflferent colors, and one of the compounds being a compound of nickel. In a preferred'form oi the invention, there are three emulsion layers containing metal compounds sensitised respec- -tively to light of the three wave-length regions an customary in the three-color process and the metal compounds are so selected that the images which they produce are in colors complementary to the wave-length regions to which their respective emulsion layers are sensitised.

In one form of a multi-color materialaccording to the invention, the metal compounds initial- 1y added are such that they are all converted to salts which will react with the silver salts by treatment of the material with a single solutioh. 30

The invention includes the method of treating photographic material as described above which has been exposed and developed to form a colored picture which comprises the steps of bleaching the silver image or images, converting the metal compound or the metal salt in each layer when there is more than one layer containing the metal compound, into a salt of the metal which will react with the silver salts produced by bleaching the silver image to provide a reaction treatment, be converted intoa colored product and allowing or causing the salts to react in that way.

The material according to the invention may be used for taking in the camera or it maybe used for printing and, with the selection of'suitable metal salts, it may be arranged to provide all the images in two, three or four color processes or it may be arranged to provide only some 50 of the images and other processes be relied upon to provide the remaining images. The further description of the invention will be directed to the application of it to three-color processes.

In the preferred form of this application of I .ment forms the blue constituent of the finished print, the green-sensitive emulsion containing a yellow water-soluble dye such as auramine and a metal compound which upon subsequent treatment forms the magenta'constituent of the finished print and the blue-sensitive emulsion layer containing a metallic compound which upon subsequent treatment forms the yellow constituent of the finished print. The; dyes may, if mired.

be contained in separate layers applied to the sensitised emulsion layers instead of being incorporated in said emulsion layers.

The metal compound in the blue-green image emulsion layer (1. e., the red-sensitive emulsion) may be a ferric compound, e. g., ferric hydroxide or ferric carbonate; the metal compound in the magenta image emulsion layer (i. e., the greensensitive emulsion) may be a nickel compound, e. g., nickel carbonate ornickel hydroxide, .while the metal compound in the yellow'image layer may be a lead salt such as lead carbonate.

After exposure of the coated support under suitable conditions, the print is developed as in normal black and white printing, fixed and then print, in section, at four stages in the method and sets out briefly the intermediate process steps.

The paper or other support is first coated with a stripping layer and then with a layer of emulsion sensitised to red (for example with Dicyanin or Pinacyanol). This layer also contains a proportion of ferric hydroxide and a pink, watersoluble, dye acid magenta. A second layer of emulsion sensitised to green (for example with Pinaverdol or Erythrosin) and containing a proportion of nickel carbonate and a yellow watersoluble dye such as auramine is applied to the first and this is 'followed by a blue-sensitive emul-v sion layer containing a proportion of lead carbonateZ -The coated material 'is' shown at the first stage'in Figure 1.- The proportions of ferric hydroxide, nickel carbonate and lead carbonate added to the layers are just suiiicient to convert all the silver salts by the treatment later described.

The composite printingsensitive material is exposed in contact with the multi-color trans-v parency and upon development of the print three -positive images will be formed, one in each layer of the emulsion and each recording only one color of the ncy. This composite print .nide bath which converts the silver in each of the layers into silver ferrocyanide and washed the yellow at the bottom.

and dried. The print is then treated with dilute hydrochloric acid which converts the ferric hydroxide in the bottom layer irto ferric chloride and this combines with the silver ferrocyanlde in this layer to form a blue image of ferric ferrocyanide. Simultaneously, the nickel carbonate in the second layer is converted to soluble nickel chloride which forms nickel ferrocyanide with the silver ferrocyanide in this layer. After washing, this is converted to the-magenta nickel dimethylglyoxime by treatment with a solution of the composition. given later of dimethylglyoximo and triethanolamine. The print is then treated with a solution of potassium chromate which converts the lead ferrocyanide in the top layer into yellow lead chromate. The print is now at the third stage shown in Figure 1. The print may then be transferred to a permanent base and the original paper support stripped OK, as shown at the fourth stage in Figure 1.

The light used for printing is obtained from a discharge lamp of the kind shown under the registered trade-mark Osira. The lamp provides light which, in addition to the normal mercury vapour spectrum giving prominent lines in the green and blue region, embodies the spectrum of cadmium vapour giving the well known cadmium red line. The composite. radiation from the lamp is filtered by the use of a didymiumchloride liquid filter or a glass filter which has the same property of absorbing radiation wavelength bands in regions where there may be excessive overlap in the spectral transmission of the primary filter elements of the mosaic screen. Exposure is carried out in one of three ways. The light produced by the la p may be arranged after passing through tire filter to illuminate diffusely the original and copy materials in contact, or successive exposures varying in time 'may be made incorporating successively-standard commercial tri-chromatic filters between the filterdescribed above and the master transparency or a rotating filter disc can be used between the filter described above and the master, the disc being provided with tri-chromatic filters selected as to their dimensions'or densities to give the desired relative exposures.

In a modified form of the process described in the above example, the uppermost layer (the bluesensitive yellow image layer) consists of a normal emulsion with no addedmetal salt as shown in Figure 2, the image being toned yellow byany yverting it to lead ferrocyanide by treatment in the following solution of a soluble lead salt:

Lead acetategms 40 Glacial acetic acid ccs 100 Water to make ccs 1000 'The material is then washed well and treated in a. 1% solution of potassium chromate to convert the lead ferrocyanide to yellowlead chromate. I

Alternatively, the silver 'ferrocyanide may be treated with a 2% solution of mercuric potasslum iodide to convert it'to the yellow mercury salt. As the layer of mercury salt is somewhat opaque it is generally desirable, when this process is used, to transfer the entire print to a fresh support so that the blue layer is on top and In a further modified form of the above extwo layers are transferred to the yellow toned 2,197,994 ample the red-sensitised layer containing ferric tised layers may either be coated on the same ing, bleaching in'a ferricyanide bath to form silver ferrocyanide, and bathing in hydrochloric acid to convert the ferric hydroxide to ferric chloride, which combines with the silver ferro- 1 cyanidein its layer to form blue ferric ferrocyanide, and also to convert the nickel .:te to nickel chloride, which forms nickel ierrocyanide in its layer. The nickel ferrocyanide is then as before, converted to nickel dimethylglyoxime to give blue and magenta images respectively in the two layers.

The independent blue-sensitive layer is developed and toned yellow by any convenient means, such as those described above and the combined blue and magenta images are then secured to the yellow image to provide the complete picture.

It is preferred to use silver chloride emulsions for the severallayers which contain metal salts but silver bromide emulsions may be used and when a separate blue-sensitive layer is used and is toned yellow, it is convenient to use a bromide emulsion for this layer.

According to another example of thejnvention, a red-sensitised layer containing ferric hydroxide is coated on a support as described above and on top or this is coated a green-sensitised layer without added metal salt as shown in Figure 5. The blue-sensitised layer is applied to a separate support and is treated as described'above.

After exposure, the redand green-sensitised layers are developed, fixed and bleached in a rerricyanide bath as before. The layers are then treated for about 5 minutes in a bath of:

- by weight Saturated chrome alum solution so Hydrochloric acid (sp. gr. 1.16) 10 Nickel chloride solution (20%) .L 40

The treatment in this solution converts the image in the bottom layer to blue ferric ferro- Parts by weight Dimethylglym 2 Triethanolami 200 Water 800 This bath converts the nickel ferrocyanide to the magnets. nickel dimethylglyoxime and after clearing in a 1% acetic acid bath and fixing in hypo to remove any remaining silver salts the third layer.

As stated above-the color filters appropriated to the red-sensitive layer and to the green-sensitive layer may be contained as water-soluble dyes in separate layers applied to the respective emulsion layers, and the layers containing the dyes may contain compounds which act as pie-:-

cipitating agents for the metallic compounds in contiguous layers, thus preventing the wandering of the metallic compounds from one layer to another.

Although the production of color prints from a colored mosaic transparency developed as a negative has been described above, prints may also be made by reversal from a transparency developed as a normal positive. Further, the invention, in its application to the production of copies, .is not'restricted to the copying of mosaic additive transparencies but may be applied to the copying of subtractive images.

It will be understood that by the use of a transparent yellow the process may be applied to the printing of transparent positives, e. g,, for cinematograph films. Y

The multilayer film made in accordance with the invention may be exposed in a camera and developed as a negative in complementary colors to the original subject. Prints may then be made on the sa'me material by. direct contact or projection printing.

I claim: l. The method of producing a multi-colored photograph from light sensitive photographic material composed of a support and at least three inseparably superposed light sensitive silver halide emulsion layers which have been exposed to record, respectively, red, green and blue aspects of the subject and which respectively contain a ferric compound, a nickel compound and a le'adcompound which comprises the steps of developing all the layers to produce silver images,

converting all the silver images to silver ferrocyanide, treating the material with hydrochloric acid to convert the ferric compound into ferric chloride, the nickel compound into nickel chicride, and the lead compound into lead chloride, allowing the ferric, nickel and lead chlorides to react with the silver ierrocyanide in their re-' spective layers to produce blue ferric ferrocyanide, nickel ferrocyanide and lead ferrocyanide, treating the material with dimethylglyoxime to convert the nickel ferrocyanide to magenta nickel dimethylglyoxime and treating the material with potassium chromate to convert the lead ferrocyanide to yellow lead chromate.

2. The method of producing a multi colored photograph which comprises making separation records of the red, green and blue aspects of thesubiect by exposing light sensitive photographic material having at least three appropriately color sensitive silver halide emulsion layers inseparably carried on a support and containing respectively a ferric compound, a nickel compound and a lead compound, developing the exposed layers to form silver images, converting all the silver images to silver ferrocyanide', treating the material with hydrochloric acid to convert the ferric compound into ferric chloride, the nickel compound into nickel chloride, and the lead compound into lead chloride, allowing the ferric, nickel and lead chlorides to react with the silver ferrocyanide in their respective layers to produce blue'ferric ferrocyanide, nickel ferrocyanideand lead ferrocyanide, treating the material with dimethylglyoxime to convert the nickel ferrocyanide to magenta nickel dimethylgiyoxime and treating the material with potassium chromate to convert the lead ferrocyanide to yellow lead chromate;

3. The method of producing a multi-colored photograph from light sensitive "photographic material composed of a support and at least three inseparably superposed light sensitive silver halide emulsion layers which have been exposed to record, respectively, red, green and blue aspects of the subject and which: contain respectively ferric hydroxide, nickel carbonate and lead ride, and the lead carbonate into lead chloride,

allowing the ferric, nickel and lead chlorides to react with the silver ferrocyanide in their respective layers to produce blue ferric ierrocyanide,

nickel ierrocyanide and leadierrocyanide, treating the material with dimethylglyoxime to con-- vert the nickel ferrocyanide to magenta nickel dimethylglyoxime and treating the material with potassium chromate to convert the lead terrocyanide to yellow lead chromate.

' COLIN BUTEMENT. 

